The invention encompasses methods of reducing grain sizes of materials, and in particular applications encompasses methods of reducing grain sizes of titanium-comprising materials, aluminum-comprising materials, and/or copper-comprising materials. The invention further encompasses methods of forming sputtering targets. In a particular embodiment, the invention encompasses a method for producing a sputtering target material in which a metallic material is subjected to plastic working at a processing percentage of at least 5% utilizing a processing rate of at least 100% per second (i.e., 100%/second). In particular applications the metallic material comprises one or more of aluminum, copper and titanium.